<template>
  <div class="list" ref="wrapper">
    <div>
      <div class="area">
        <div class="title border-topbottom">当前城市</div>
        <div class="button-list">
          <div class="button-wrapper">
            <div class="button">{{city}}</div>
          </div>
        </div>
      </div>
      <div class="area">
        <div class="title border-topbottom">热门城市</div>
        <div class="button-list">
          <div class="button-wrapper" 
            v-for="item of hot" 
            :key="item.id"
            @click="handleCityClick(item.name)"  
          >
            <div class="button">{{ item.name }}</div>
          </div>
        </div>
      </div>
      <!-- 
          遍历数组：v-for="(item,index) in arr" :key="index"
          其中，item是对应数组arr里面的value值，index对象数组的下标，index值唯一
          遍历对象：v-for="(objValue,key,index) of obj" :key="index"
          其中，objValue对象对象obj的value值，与上例中的item值同理，key对应对象中的key值，例如obj里面的name，index为obj对象下标，与数组中的index同理。
       -->
      <div class="area" v-for="(item, key) of cities" :key="key" 
      :ref="key">
        <div class="title border-topbottom">{{ key }}</div>
        <div class="item-list">
          <div class="item border-bottom" 
            v-for="innerItem of item" 
            :key="innerItem.id"
            @click="handleCityClick(innerItem.name)"
          >{{innerItem.name}}</div>
        </div>
      </div>
    </div>
  </div>
</template>
  
  
<script>
import {mapState,mapMutations} from 'vuex'
import Bscroll from 'better-scroll'
export default {
  name: "CityList",
  props: {
    hot: Array,
    cities: Object,
    letter: String
  },computed:{
    ...mapState(['city'])
  },
  methods:{
    handleCityClick(city){
      this.changeCity(city)
      this.$router.push('/')//通过router中的Push方法进行路由跳转
    },
    ...mapMutations(['changeCity'])
  },
  mounted() {
    this.scroll = new Bscroll(this.$refs.wrapper,{
      click:true// 元素可触发点击事件
    })
  },
  updated() {
    this.scroll.refresh()
  },
  watch: {
    letter() {//监听letter数据
      if (this.letter) {
        const element = this.$refs[this.letter][0] 
        //this.$refs[this.letter],获取每一个字母所代表的盒子数组
        //因为是元素数组，因此需要加一个[0]进行转换为dom元素
        this.scroll.scrollToElement(element)
      }
      console.log(this.letter)
    }
  }
};
</script>
  
<style lang="stylus" scoped>
@import '~styles/varibles.styl';

.border-topbottom {
  &:before {
    border-color: #ccc;
  }

  &:after {
    border-color: #ccc;
  }
}

.border-bottom {
  &:before {
    border-color: #ccc;
  }
}

.list {
  overflow: hidden;
  position: absolute;
  top: 1.58rem;
  left: 0;
  right: 0;
  bottom: 0;
}

.title {
  line-height: 0.44rem;
  background: #eee;
  padding-left: 0.2rem;
  color: #666;
}

.button-list {
  padding: 0.1rem 0.6rem 0.1rem 0.1rem;
  overflow: hidden;

  .button-wrapper {
    float: left;
    width: 33.33%;

    .button {
      text-align: center;
      margin: 0.1rem;
      padding: 0.1rem 0;
      border-radius: 0.03rem;
      border: 0.02rem solid #ccc;
    }
  }
}

.item-list {
  .item {
    line-height: 0.76rem;
    padding-left: 0.2rem;
  }
}
</style>